UTTER ET AL.: STOCK COMPOSITION OF 1983 CHINOOK SALMON 



DISTRIBUTIONS OF STOCK GROUPS 

 IN OCEAN FISHERIES 



Estimated contributions to different fisheries by 

 the two tule and three upriver bright subgroups, and 

 by the four other geographic groupings, are Hsted 

 in Table 3. Some of the major features of Table 3 

 are graphically projected in Figure 2. A stock struc- 

 ture that varies with regard to both time and area 

 is evident. 



Some consistency over time is seen in comparisons 

 of the May and July commercial troll catches in sam- 

 pling areas 2 and 4. Notable features in sampling 

 area 2 include the overall predominance of the tule 

 stocks and a minimal contribution of Puget Sound 

 and Canadian fish. Sampling area 4 has a smaller 

 tule contribution and a substantially larger propor- 

 tion of Puget Sound and Canadian fish. 



Although comparisons of the sport and commer- 

 cial fisheries are limited by somewhat different 

 sampling areas, a greater proportion of California 



fish is taken in the sport fisheries. This is seen par- 

 ticularly in the early fishery. More intense sam- 

 pling in area 1 may account for some of the early 

 differences, but the data of Table 3 suggest a per- 

 sistent trend even in common times and sampling 

 areas. 



The Indian troll fishery provided the only infor- 

 mation from sampling area 4B. The most distinc- 

 tive feature of this fishery was the high proportion 

 (41%) of the Puget Sound and Canadian group. This 

 figure was more than double the estimated contribu- 

 tion of this group in any other fishery. 



The ocean fisheries off the Washington coast are 

 notable for the usually negligible representation of 

 upriver bright stocks. The highest estimated contri- 

 bution (9.6%) occurred in the sport fishery of 16 

 August- 11 September which was the largest fishery 

 sampled. The timing and distribution of upriver 

 bright fish will be considered in greater detail below. 



Estimated distributions for the May 1982 and 

 1983 troll fisheries were compared (Table 4), reveal- 



California 



Washington-Oregon coast 

 Puget Sound British Columbia 

 Other Columbia River stocks 

 Upriver brights 

 Tule-Kaiama, Cowlitz 

 Tule-Spring Creek group 



Number 

 in fishery 

 (thousands) 



////////////// 



Commercial 

 troll 



1' )' r t'l'yj'/'r^ 

 '/y///////// 



' ////////// 



Indian 

 troll 



23 



4.1 



5.7 



2.3 



Catch 



area Date 



May 



4B 



July 



May- 

 July 



/////////////////////// 



////////////////////// 

 ////////////////////// 



Sport 

 fishery 



I r 



~i 1 1 1 1 1 1 r r- 



10 20 30 40 50 



1 1 1 1 1 1 1 1— 



60 70 80 90 



— t 

 100 



n 1 9 May 28- 



'■^ ^-^ June 17 



Percent contribution to fishery 

 Figure 2.— Estimated contributions of seven stock groups in different ocean fisheries. 



19 



